The present invention relates generally to mechanical lift systems, and in particular, relates to a method and apparatus for measuring the orientation of a load during and after mechanical lift operations.
Conventional lifting systems include a plurality of hydraulic actuators having cylinders and movable pistons acting under high fluid pressure that support the underside of a load. In some cases, for example when the load is bulky, heavy, or has an uneven weight distribution, the user must take special care to eliminate the risk of the load sliding off its supports. In these cases, it is desirable to implement a system that provides a measurement of an actual load orientation. The operator can thus compare the measured orientation to a desired load orientation (e.g., level with respect to the horizontal plane). If it is determined that the load is not level, certain hydraulic actuators may be selectively adjusted until the measured load orientation substantially equals the desired load orientation.
Conventional devices measure a load orientation using a computerized system having a plurality of sensors that are mounted at select locations on the load that send electronic feedback to a centralized processor. The processor monitors the relative position of each sensor and determines whether the load is properly oriented. Alternatively, the sensors may be placed directly on the actuators to measure the amount of piston displacement. The measured load orientation is fed through an electronic communications system and output to a user display. The user can then choose to raise or lower certain cylinders to achieve the desired load orientation. Some computerized systems have the capability to accept a desired orientation as input by the user, and constantly monitor and automatically adjust the position of those cylinders necessary to achieve the desired orientation.
While such systems possess considerable capability and ease of operation, they are expensive and complex to implement, especially when installing the computerized system from one load to the next.
What is therefore needed is a simplified and cost-effective method and apparatus for measuring a load orientation that can be easily integrated into a mechanical lift operation.